1. Technical Field
The present invention relates to a substrate holder, a substrate holder unit, a substrate transport apparatus, and a substrate bonding apparatus. More particularly, the present invention relates to a substrate holder, a substrate holder unit, a substrate transport apparatus, and a substrate bonding apparatus for holding a substrate.
2. Related Art
A known substrate transport apparatus is configured to transport a substrate holder holding a substrate as disclosed, for example, in Japanese Patent Application Publication No. 2006-332563. For example, the substrate transport apparatus is utilized to transport the substrate and substrate holder to an alignment apparatus, which is configured to align the substrate held by the substrate holder with another substrate to bond the substrates to each other. The substrate transport apparatus holds the substrate holder by adsorbing means such as vacuum adsorbing means.
An electrostatic chuck designed to hold a substrate may be provided with an anti-disengagement support as disclosed, for example, in Japanese Patent Application Publication No. 08-340683. The anti-disengagement support inwardly extends from the periphery of the electrostatic chuck, and moves between an anti-disengagement position at which the support covers the substrate in a non-contact manner and a retreat position at which the surface of the electrostatic chuck on which the substrate is to be placed is exposed, by rotating around the rotation axis that extends parallel to the substrate.
According to the disclosure of Japanese Patent Application Publication No. 08-340683, however, the electrostatic chuck is secured onto an apparatus such as an ion implanter. Therefore, it is not possible to transport the electrostatic chuck out of the apparatus while holding the substrate by electrostatic force.